makeSEA 3D Printed Brushless Motor v2

by Christoph Laimer

Brushless Motor Model A001

(see also, windpowerWriter)

(see also, Selecting the Magnets)

(see also, Brushless Motor v0, prototype)

Introduction / Summary

There is 3D-printable magnetic PLA from Proto-Pasta. Some applications are published, where the material was used because of its special surface look-and-feel: e.g. make objects with a rusty patina. Is there an application, where its magnetic properties can be used? Actually it should say “ferromagnetic”, because the material is not a magnet, and it also can’t be permanently magnetized, but it’s attracted by a magnet.

With its properties the material could be very useful to 3d-print special shaped cores for electromagnetic coils. E.g. a brushless motor. First tests with the magnetic behavior of this material show, that the magnetic PLA is much less magnetic than common things made of steel. On the positive side the material is not conductive: therefore there is no danger to create short-cuts when winding the coils, and there are no eddy currents.

The resulting design is a brushless motor, which can be controlled by a common ESC from RC-toys. It’s powerful enough to drive a car (efficiency is higher than 60%). The motor can be 3d-printed with a common printer (Ultimaker, Makerbot). Non-printable parts are easy to source at ebay or other online-stores. Measurements show, that these is even more potential that could increase power and efficiency.

Components

The motor consists of 4 main parts, which are 3d-printed:

BL_StatorShield.stl

Stator Shield: Screws, Ball-Bearings, PETG or ABS (no PLA - there are potentially big vibrating forces)

BL_StatorWindingCore.stl

Stator Winding Core: for copper wires, use magnetic PLA for efficiency reasons, or otherwise a high-temperature stable material.  This design uses approximately 6m of 1.75mm filament, or about 25 grams of material, at 100% infill.

BL_Rotor.stl

Rotor: Magnets, PETG or ABS (ferromagnetic material would be great, if it could sustain high centrifugal forces). Magnetic PLA is not recommended as it’s very brittle.

BL_RotorCollar.stl

Shaft Collar, connecting the Rotor with the shaft. Recommended material is PETG or ABS.

 

Further needed non-printable pieces:

  • 1 Shaft: Diameter 5 mm, Length 90 mm, ideally hardened Steel
  • 2 Ball Bearings: Inner Diameter 5 mm, Outer Diameter 10 mm, Width 4 mm

  • 1 Shaft Collar: Inner Diameter 5 mm. Outer Diameter 9 mm, Width 5 mm, long set screw

  • 4 Nuts and Bolts, M3, Nuts 2.5 mm thick, 5.5 mm smaller Diameter

  • 12 Magnets, Length 30 mm, Width 10 mm, Thickness 2.8 mm (Chinese supplier specified 3 mm)

  • 12 m Enameled Copper Wire, Diameter 0.67 mm (approx. 50 g)

  • Connectors, cables, heat shrink tube, etc. (depending on the final application)

Winding Tool:

The tool helps while winding the wires. Wires can be taped to the handle, or excess wires can be pushed into the handle.

BL_WindingToolHandle.stl

BL_WindingToolHolder.stl

BL_WindingToolScrew.stl

Critical part is the screw: it has 1.5 mm pitch, 60° overhangs. Prints very nicely on UM2 with PETG.

Fabrication (printing, assembly)

The motor pieces are not very difficult to print, however they need to be as accurate as possible. Use high resolution settings, print at slow speeds. Centrifugal forces are high and unbalanced parts can cause big vibrations, noise, or maybe the motor can be destroyed.

Rotor:

Needs to be well balanced. The hole for the shaft in the 3d-model is exactly 5 mm, and when printing, it will usually be a bit smaller due to printing inaccuracies. That’s desired, because the shaft needs an accurate tight fit in the rotor. Use a drill press to adjust the bore exactly to the shaft. Don’t drill at high speed, as this would cause the 3d-printed material to melt. Also drill out the hole of the 3d-printed shaft collar, insert the metal collar into it, and use a long grub-screw, in order to fix both (metal, and 3d-printed) collars to the shaft.

Insert the magnets with alternating polarity into the slots of the rotor. In order to well balance the rotor, it’s recommended to weight the magnets before assembling, and position magnets with similar weight at the opposite slots. E.g. if magnets are sorted by their weight, they could be inserted in this sequence: 1, 4, 5, 8, 9, 12, 2, 3, 6, 7, 10, 11.

Stator:

Insert the nuts into their space. Nuts and front ball bearing are very close together, and they should be able to sustain a bigger load (because the plastic stator isn’t as stiff as if it was made of metal, it’s recommended to connect the pulley / propeller near to the front bearing). The stator winding core slides simply onto the designated rails. There are big gaps to allow sufficient air-flow. Plastic will not sustain high temperatures, and since inferior efficiency is expected (compared with a common brushless motor), it’s very important to carry aways all the heat. Push the ball bearings into their designated space. The winding core is held in place by the rail-friction and the cables (or a bit of glue if needed). Before finally attaching the winding core, the wires need to be wound.

Winding the Stator

The stator has 36 slots. In each slot there finally need to be 6 wires (the illustration below shows only 4 wires and only phase A for simplicity reasons).

The basic scheme is very simple. There are three coils resp. Phases (A red, B green, C blue). In each slot the current of all the 6 wires needs to flow into the same direction (current in opposing directions neutralizes its effect and is not desired). Continuous lines in the illustration are wires in the foreground, dotted lines are wires in the background. The big dots indicate wires in the slots, from front to back (or reverse). The “plus” in the circle indicates the direction from front to back, the “dot” in the circle indicates the opposite direction.

While the basic scheme is simple, the actual winding is a bit more complex. The main problem for winding an electrical motor isn’t the small space for wires in the slots, but all the overlapping and crossing wires going from one slot to another slot. Wires are passing in front of other slots and therefore block the entry for other wires … In order to resolve this, the winding is mixed in lower and upper layer turns. I.e. There are 4 lower layer turns (only 2 are illustrated), and 2 upper layer turns (as illustrated).

 

  • Start wiring with the red wire in slot #1. Keep 15 cm extra wire, slide it through a hole in the winding handle, and fix it with tape. For all 6 lower layer coils, make 4 turns (only 2 illustrated in the picture).

  • When all the big 6 lower layer coils are completed with four turns at slot #4, make a “pause”: i.e. cut the cable with 1.5 m excess wire, fold it, and push it into the handle.

  • Do the same with the green wire starting at slot #3. The pattern is exactly the same as for the red wire just 3 slots shifted. Also pause after the lower layer coils at slot #6.

  • Do the same with the blue wire starting at slot #5, and pause st slot #8

  • Continue with the red wire (remove it from the winding handle), do 2 upper layers: continue to slot #1 go back leave 2 slots empty, go front, leave 2 slots empty, go back, etc.

  • Do the same for green and blue wires.

In principle it’s possible to change the scheme as long as the current flow direction and phase per slot matches with the illustration (e.g. only the upper layer scheme with 6 turns).

Once all the wires are in the correct slots, the wires probably need to be well aligned, and they should not sick out of the stator (the moving rotor will touch and damage badly placed wires). In order to push and bend the copper wires, never use metal. Better use wood, or plastic (you can 3d-print a “credit-card”).

Finally trim all the 6 wire ends to the same length and remove 5 mm of it’s isolation. Later all the 3 “start” wires can be connected and soldered together (Wye- resp. Star-Connection). The image below illustrates the Wye-connection (not the actual winding):

Maybe you want to experiment with Delta-connection (triangle). For more information see https://en.wikipedia.org/wiki/Brushless_DC_electric_motor#Variations_in_construction

When sliding the winding core onto the Stator-Shield, the wires can be either guided through the vent-holes (for testing) or through the small holes the the side (final wiring).

  

Basically the motor is now finished. The rotor firmly connected with its shaft can be pushed into the ball-bearings. The magnets pull it over the stator. In order to prevent the stator from moving out of the bearings, the pulley (or propeller) needs to be mounted on the front shield.

Tests and Measurements

Now it’s time for the truth. It will turn, but how well will it perform?

Before connecting a motor to a power source, it’s best to check with a multimeter, if there are no short-circuits between the wires. The 3 wires need to have all the same resistance.

Wire Length per Phase (approx.)

3500

mm

Wire Diameter

0.67

mm

Resistivity Copper

0.017

Ohm*mm^2/m

Resistance per Phase (calculated)

0.17

Ohm

Resistance per Phase (measured)

0.19

Ohm

That was the simple test - next is the estimation of the expected rotations per minute (RPM). If the motor rotates too fast, things can get really dangerous. The centrifugal forces can get really high, and the rotor maybe “explodes”. Magnets become dangerous projectiles and potentially cause serious injuries. Therefore: Never stay in the plane of rotation! Remain either in front or behind it! But for safety reasons we’re going to test the motor first as generator: fix the shaft at electric drill, and connect the two ends of the red wire A to a scope (or a multimeter).

On the scope it’s simple and accurate to measure amplitude voltage and frequency (can be transformed to RPM). With a simple multimeter you would need to measure AC-voltage, and the RPM from the drilling machine specifications.

The yellow curve is the generated voltage from a single phase (e.g. the red wire). The green curve is the generated voltage from the two other wires (blue and green) connected in series, similar to the star-connection scheme. The measured frequency is 102 Hz - with 12 magnets of alternating polarity the frequency needs to be divided by 6 in order to get the generator revolution speed.

Rotation Speed

1’023

RPM

Amplitude Delta-Connection

0.595

V

Amplitude Star-Connection

1.07

V

Kv (Star-Connection)

1’006

RPM / V

Running this motor with 6 Cells NiMH (nominal 7.2 V) will result in 7’000 to 8’000 RPM - which is slow enough to not explode (there is a “funny” video on YouTube, where a 3d-printed rotor explodes at 36’000 RPM). This test also passed, and the motor was connected with the ESC from a RC-car. Without load the motor spins well, draws approximately 0.5 A from the battery. And it obviously has power reserves.

The ultimate test requires a more complex setup: need to measure efficiency with some load attached. As load a regular propeller was attached (10 inch diameter, 4.5 in pitch) - beating the air is a simple way to waste the motor shaft power. The simplest way to measure input power is right at the battery: voltage and current. The final output shaft power can be measured by multiplying rotation speed and torque (times PI). RPM is measured with a laser beam and a reflecting tag fixed at the rotor (can be ordered for a few $ at ebay). Torque is more challenge, but with some physics, math, and a construction with a 20cm long lever and a scale measuring at a resolution of 0.1 g it can be calculated.

Here are the numbers:

(measured)
Battery Current (A) Battery Voltage (V) Motor Speed (RPM) Motor Force (g)
0.01 7.83 0 0.02
0.45 7.66 1'880 3.1
0.71 7.65 2'260 4.4
1.3 7.6 2'970 7.1
1.95 7.56 3'440 9.6
2.95 7.52 4'020 13.8
3.6 7.45 4'430 16
4.3 7.39 4'720 18.5
5 7.35 4'990 20.3
5.65 7.4 5'250 24

 

(calculated) (result)
Motor Torque (Nm) Battery Power (W) Motor Shaft Power (W) Efficiency
0.000 0.08 0.00 0.00%
0.006 3.45 1.20 34.74%
0.009 5.43 2.04 37.62%
0.014 9.88 4.33 43.85%
0.019 14.74 6.79 46.03%
0.027 22.18 11.40 51.38%
0.031 26.82 14.56 54.30%
0.036 31.78 17.94 56.46%
0.040 36.75 20.81 56.63%
0.047 41.81 25.89 61.92%

 

And here is the plot:

With 5 A Battery current and roughly 35 W power consumption, the overall system efficiency is at 60%. That’s not too bad - the losses also includes losses from the ESC and all the cables! The efficiency of the motor itself is therefore bigger than 60%. The values seem plausible - running the motor for several minutes at full throttle (5.6 A) does not dramatically heat up the motor. Final temperature is 30°C (with 20°C room temperature).

Also the measured torque makes sense:

Torque increases almost perfectly with the square of the speed. This is a common behavior in aerodynamics.

Conclusions

Since the measurement methods are done with very simplistic manual methods, the measurement accuracy couldn’t be properly checked. Maybe the mistake could be bigger than 10%. It would make sense to repeat this with more professional instruments.

It would be interesting to measure the effect of the magnetic PLA. How much worse is the efficiency if the stator was printed with normal PLA? Can the efficiency be increased by using magnetic PLA for the rotor?

The motor definitively produces power enough to move a RC-car. Is it also enough for a small RC-plane?

The motor can digest more current (assumingly 7A - 10A) before it has a temperature problem. Which is the maximum power (watts) that the motor can produce? What happens with double voltage and higher RPM using a smaller propeller as a load (with the same propeller the current would quadruple > 20 A)?

Number of slots, number of poles and winding pattern is a science. There is almost an endless number of combinations. For this motor a “simple” scheme was selected, where wires can be placed close to the magnets (compensate the inferior material properties for the magnetic flow). The design is an heuristic approach, and certainly not the optimum. What’s the theoretic optimum using magnetic PLA from Proto Pasta?

Datasheet

Diameter

52.2

mm

 

Continuous Power

42

W

Length

54.0

mm

 

Nominal Voltage

7.4

V

Overall Length (incl. Shaft)

86.8

mm

 

Nominal Current

5.6

A

Shaft Diameter

5.0

mm

 

Nominal Efficiency

62

%

Screw Hole Distance

25.0

mm

 

Nominal Speed

5’250

RPM

Screw Thread Size

M3

   

Nominal Torque

0.047

Nm

Weight

220

g

 

Stator Height

30

mm

Resistance per Coil

0.19

Ohm

 

Stator Diameter (air gap)

40

mm

Poles

12

         

Slots

36

         

Turns

3

         

Wire Diameter

0.76

mm

       

Kv

1’006

RPM / V

       

 

Links

https://en.wikipedia.org/wiki/Brushless_DC_electric_motor

https://www.youtube.com/watch?v=bCEiOnuODac

http://www.bavaria-direct.co.za/

Videos

/documents/12185/40127/20160410_201057.mp4

/documents/12185/40127/20160411_110702.mp4

 

3D Printed Brushless Motor v2

Brushless Motor Model A001.1

Introduction

The first real working 3d-printed motor “makeSEA Model A001” is a good starting point for the next level. The measured graph with its efficiency indicated, that it must be possible to get more power out of this design. In fact changes of the stator and the copper wire made it possible to create a brushless motor with almost 65% efficiency at 90W. The rotor remains unchanged - the same as “Model A001”.

Components and 3d-Printing

The components are all the same like the basic Model A001 except the stator. The stator is divided into two mirror symmetric parts. The division allows to 3d-print it without the need of support-material. The two parts are held together with the copper wire.

BL_StatorWindingCoreA.stl

BL_StatorWindingCoreB.stl

3d-printing with magnetic PLA from Proto Pasta works straight forward. Extrusion temperature is 200°C. The two halves can be printed at the same time.

 

As the Stator external dimensions didn’t change, all other parts from “Model A001” can be re-used: BL_StatorShield.stl, BL_Rotor.stl, BL_RotorCollar.stl. The same shaft, ball-bearings, shaft-collar, nuts, and magnets can be used. Only difference is the copper wire:

  • Enameled copper wire: 1 mm diameter, approx. 10 m length (weight 60 g)

Stator Design and Winding

The stator winding core is completely redesigned. Only the number of slots (teeth) is unchanged. The length if the teeth is shorter. The head of every second tooth has a special shape, which helps to guide the overcrossing wires, hold them firmly in the slots. Thus winding is simpler, and no extra winding tools are needed - however the thicker wire diameter feels stubborn, and requires much more force. It can happen that the tooth-head breaks (magnetic PLA is very brittle). The heads are not relevant for the motor functionality, and just in case the wires can also be fixed with some strong tape (e.g. glassfiber reinforced tape - the author’s solution).

Each slot of the new stator has space for 4 wires. The illustration shows only 2 wires and only one phase for simplicity reasons. Continuous lines in the illustration are wires in the foreground, dotted lines are wires in the background. The big dots indicate wires in the slots, from front to back (or reverse). The “plus” in the circle indicates the direction from front to back, the “dot” in the circle indicates the opposite direction.

Before actually starting the winding of the magnetic PLA core, it’s recommended to exercise with some cheaper material. Maybe a test-print in ABS. Even though the winding pattern is not complicated, it’s not suited for beginners.1 Take your time - accurate and well fitting wires make it simpler to do the final turns.

1. I would recommend starting with thinner wire as it will be easier to get an accurate winding, and it will still yield power, just not as much as if you were to use thicker wire. Once you have tested the motor with the thinner wire then move onto the thicker wire. - D. Hartley

  • Cut the copper wire into 3 pieces, each approximately 2.5 m long. Coil it on 3 small spools. These are the cables for phases A, B, and C.2 

2. I would recommend starting with a full spool of wire and start the winding with phase A. Each set of winding requires approximately 2.5 m of wire, but it is much easier to wind the core using the spool as a tool to move the wire around. -D. Hartley

  • Start winding phase A (red) with slot #1 on the front. Make sure the selected slot has a shape, where the cable is guided over the tooth-head between slot #1 and slot #2 (and not at the side). Position the wire into slot #1, and bend it on the back of the stator over the tooth-head towards slot #4. Wind the wire at the side of the tooth-head between slots #3 and #4. Position the wire into slot #4, and bend it then back toward slot #1. This was one turn. Repeat it 4 times (slots #1 and #4 will each have 4 wires). With the last turn, don’t bend the cable back towards slot #1 - the next slot would be #7,3 but we make a pause and continue with phase B (green). In order to fix the remaining cable, it can be temporarily positioned diametral into slot #22.

3. Continue with Phase A until you have finished the winding with the wire coming out of slot #34. -D. Hartley

  • Continue winding phase B (green) starting with slot #3 (slot #2 will remain empty at the moment). Position it into slot #3 and slot #6. Do exactly the same as previously described for phase A, just with 2 slots offset. Use slot #24 as temporary fix.
  • Continue analogous with phase C (blue) with slots #5 and #8.
  • Slots #1, #3, #4, #5, #6, #8 are now all filled with 4 wires per slot. It’s time to continue with phase A (red), which had been temporarily fixed in slot #22. Reposition it to slot #7. This is the only bend, where the cable is not as well guided. Continue with the same winding patterns as initially, but now in slots #7 and #10. Again 4 turns. Then phase B, C. And so on …
  • The very final turns of phase C (blue) are a bit more tricky. The pattern is the same, but the cables need to be led through the first coil of phase A.
  • Done! Tea-time :-)

In the picture above one tooth-head is heavily bent upwards. It finally did break off. No real tragedy - it looks bad, and the unguided cables are more difficult to restrain, but the final functionality of the motor is not affected.

The 3 images below also illustrate the same the winding scheme. The three phases are colored in copper, gold, and silver. Instead of 4 individual wires, the illustration shows only a single fat wire per slot (easier visualization).

When all the winding is completed (after tea-time), the cables probably need to be pushed to their final position. Use a piece of wood or plastic, but no metal as it would damage the wire isolation. The rest of the assembly is the same as for makeSEA Model A001. It’s recommended to guide all the 6 ends out of the case, and connect it in a star-shape.4

4. Personally I used a credit card and toothpick and it worked great.

Tests and Measurements

The measurements are performed similar as for Model A001. Therefore less comments, and pure numbers.

 

Wire Length per Phase (approx.)

2200

mm

Wire Diameter

1.0

mm

Resistivity Copper

0.017

Ohm*mm^2/m

Resistance per Phase (calculated)

0.047

Ohm

 

Generator test (“drill-press method”) for measuring Kv:

Rotation Speed

1’060

RPM

Amplitude Delta-Connection

0.5

V

Amplitude Star-Connection

0.83

V

Kv (Delta-Connection)

1’344

RPM / V

Model A001 had Kv = 1’006 RPM / V with 3 turns per tooth. If the old stator was wound with only 2 turns per tooth (like the new stator), the motor had 1’509 RPM / V. Obviously the shorter teeth had their desired effect: less RPM, and more torque (and hopefully more efficiency).

OK! Mount the propeller, and connect the motor with the ESC from the RC-Car. Pushing carefully the throttle, the motor starts immediately and sounds “normal”. More throttle while continuously measuring the RPM - in order to be sure, the motor doesn’t exceed 10’000 RPM (which is hopefully a limit, where centrifugal forces are still small enough and the motor doesn’t break). At full throttle the current at the battery is 13 A and the motor spins approximately with 7’000  RPM. The propeller makes a powerful sound, generates a lot of airflow in the workshop (swirling all the dust). This is very promising. A whole series of measurements including the motor torque was taken. Again the same setup as for the previous Model A001.

 

(measured)

(calculated)

(result)

Battery Current [A]

Battery Voltage [V]

Motor Speed [RPM]

Motor Force [g]

Motor Torque [Nm]

Battery Power [W]

Motor Shaft Power [W]

Efficiency

0.55

7.65

1'500

2.8

0.005

4.21

0.86

20.51%

0.7

7.65

2'120

4

0.008

5.36

1.74

32.54%

1.04

7.64

2'450

5.4

0.011

7.95

2.72

34.21%

1.5

7.6

2'970

8.16

0.016

11.40

4.98

43.68%

2.08

7.58

3'400

10.2

0.020

15.77

7.13

45.19%

2.5

7.6

3'640

13

0.026

19.00

9.72

51.17%

3.3

7.5

4'030

15

0.029

24.75

12.42

50.18%

5

7.5

4'750

20.5

0.040

37.50

20.01

53.35%

6

7.33

5'150

24.8

0.049

43.98

26.24

59.67%

7.1

7.37

5'500

26.8

0.053

52.33

30.28

57.88%

8.5

7.2

5'880

32.1

0.063

61.20

38.78

63.37%

9.3

7.21

6'150

35.8

0.070

67.05

45.24

67.46%

10.5

7.1

6'400

38.5

0.076

74.55

50.63

67.91%

12.45

7

6'750

42

0.082

87.15

58.25

66.84%

13

7.1

6'924

42

0.082

92.30

59.75

64.73%

 

 

 

 

With 13 A Battery current and roughly 90 W power consumption, the overall system efficiency is at 65%. That’s more power and better efficiency compared with Model A001. The losses also includes losses from the ESC and all the cables! The efficiency of the motor itself is therefore bigger than 65%. The values seem plausible - running the motor for several minutes at full throttle (13 A) does not dramatically heat up the motor. Final temperature is 40°C (with 20°C room temperature).

Comparing torque and speed: It underlines again the plausibility of the measured values.

Conclusions

Mission accomplished. Much more than 40°C is probably not healthy for the PLA stator. If the power was doubled, while the efficiency was unchanged, the temperature would probably go up to 60°C (PLA starts deforming). Further optimisation of efficiency would be required. However more than 80% is probably not realistic for a 3d-printed motor. Without changing the motor dimensions there are some options to increase the maximum power:

  • Design with better cooling
  • Maybe there is magnetic ABS or PETG? Or even leave away magnetic particles but use a material which can withstand higher temperatures up to 100°C?
  • Use magnetic material for the rotor, use stronger magnets
  • More copper, better filled slots (e.g. 3 turns with 0.85 mm wire)
  • Even shorter teeth, cables not farther than 1 mm from the magnets

For a relevant increment of power the dimensions need to be increased. Larger diameter: e.g. 24 magnets, 72 slots, higher stator: e.g. 60 mm => Volume is 8 times larger. Maximum power is theoretically also 8 times higher, but cooling surface is only 4 times larger. Guessing power in the range from 500 W to 1 kW.

Datasheet

 

Diameter

52.2

mm

 

Continuous Power

92

W

Length

54.0

mm

 

Nominal Voltage

7.1

V

Overall Length (incl. Shaft)

86.8

mm

 

Nominal Current

13

A

Shaft Diameter

5.0

mm

 

Nominal Efficiency 

65

%

Screw Hole Distance

25.0

mm

 

Nominal Speed

6’920

RPM

Screw Thread Size

M3

 

 

Nominal Torque

0.082

Nm

Weight

220

g

 

Stator Height

30

mm

Resistance per Coil

0.047

Ohm

 

Stator Diameter (air gap)

40

mm

Poles

12

 

 

 

 

 

Slots

36

 

 

 

 

 

Turns

2

 

 

 

 

 

Wire Diameter

1.00

mm

 

 

 

 

Kv

1’344

RPM / V

 

 

 

 

No Load Current (I0)

1.9

A

 

 

 

 

 

Related Videos:

RC Plane with 3-d printed motor and 3-d printed propeller

For our Spanish speaking members check out these videos by Manes Fernandez Cabanas, Associate Professor at the Universidad de Oviedo. He has documented his construction of the makeSEA brushless motor in a two part video on YouTube:

Part one is an overview of the project and the rotor.

Part two is about winding the stator.


Average (61 Votes)

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Hi Christoph Laimer,

Great Project Awesome Documenting The Steps İ Love it emoticon
Ty For Sharing.
+3 (3 Votes)
Posted on 10/6/16 12:36 AM.
Hi Christoph, great article love to see it work.. would like to try and duplicate the whole process while learning to improve this. Hope u could highlight some info on where we can buy the non printed item that u use in this motor built. Especially the exact shaft, bearing & magnet. And some quick question, do we need to insulate the stator since we use magnetic PLA/ABS?..i learn from some sites they advice to insulate this to prevent the enameled wire from short circuit while winding. But that is with the stator being built from layers of conductive metals. Please advice on this
0 (0 Votes)
Posted on 12/27/16 6:44 PM.
Hi Mr.Laimer!!!!
This is amazing work and very well documented.
I can't wait to print one motor of my own.
All the best for your future projects.
David Tsapakis
0 (0 Votes)
Posted on 1/4/17 1:43 PM.
hi Chris, this looks great! I'm trying to collect the pieces not printed, i can't find a collar thats 5mm ID, 9 OD, and 5 wide. any suggestions where to find that? Thanks!
+1 (1 Vote)
Posted on 1/4/17 3:13 PM.
Hello... If somebody have made quadcopter then please tell me I also want to know if this motor will be powerful enough to fly a plan or quadcopter...
+1 (1 Vote)
Posted on 1/19/17 11:07 AM.
Great work!!
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Posted on 1/27/17 8:31 AM.
Hi Key, We would love for you to try and let us know! Please see the video above for a demonstration of the motor in an RC plane application. A quadcopter may be more challenging because of the lift forces involved. But, please keep us posted on any discovery that you do and be sure to post your work to makeSEA so others can share, too!
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Posted on 1/27/17 6:08 PM in reply to Key Looger.
Hello Christoph,

For me you are one of the best 3d designers.
I'm a 3d printing newbie but when I got into this hobby, the kind of projects you published here was what I had in mind.
Unfortunately there isn't much out there at least it's what google makes me believe, which indirectly makes you that much more special.

My next big project is this motor, I'll let you know if I succeed. emoticon

Please keep it up!
If you have a Patreon account let me know!
Hope you can continue to do what you like for as long you want.

Best regards from Portugal,
Braulio Silva
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Posted on 1/28/17 7:12 AM.
It was easier to just pick up the 10mm on amazon and update the STL, might be at easier route for some folks. I couldn't get the 18 gauge wire in the stator, that stuff is tough, I broke most of the top guides. Ive just completed the second stator with 20 gauge, i have it fully assembled, just need to start testing!
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Posted on 2/1/17 9:05 AM in reply to eric eric.
Hi Eric we are excited to hear your results - and definitely encourage tweaking the dimensions to match parts you can find at the local hardware store.

As for the windings, we are using smaller gauge wire for the generator application because it produces a useful current at lower rpm for the wind turbine Arduino controller. We have found that changes the performance as a motor, a bit, but it should still work. See the Wind Turbine project wiki for more information. Please be sure to share your experience, too! - you can post a blog on your Profile page.
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Posted on 2/1/17 11:02 AM in reply to eric eric.
Very interesting project. Question: do I understand correctly that the winding code can be printed in non-magnetic material? Would PETG be ok? I'm not a fan of ABS.
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Posted on 2/4/17 4:56 PM.
I didn't test it with the motor in particular, but I've done some measurements with a single coil (http://www.makesea.com/wiki?p_p_id=54_INSTANCE_9jGVcyv6Jb3y&_54_INSTANCE_9jGVcyv6Jb3y_title=makeSEA+Analysis+-+Magnetic+PLA+-+Electromagnetic+Tests). My prediction is, that the motor will spin 10% faster with PETG. I can't predict the efficiency, but I guess it's not much less compared with the magnetic PLA.
+1 (1 Vote)
Posted on 2/5/17 3:13 AM in reply to JD Begin.
Is it possible to run the motor without access to an rc car's esc?
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Posted on 2/5/17 6:21 PM.
A brushless motor requires 3-phase AC with variable voltage and frequency. There are alternatives, but an ESC ist most simple, reliable, and cheap.
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Posted on 2/6/17 6:17 AM in reply to JD Begin.
I just finished mine today but it won't turn! I have no idea why. Powered up using 1/5 Baja 5T. Is there a wiring diagram somewhere? I am confused about the six wires sticking out, I modeled my winding to the "copper, gold, and silver." image. I am not entire sure which one is positive, negative, signal??? PLEASE HELP!
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Posted on 2/8/17 9:46 PM.
Hi Michael - sorry to hear it is not turning as expected. Here's a few suggestions to check: Make be sure your wire is insulated, and the inner leads are connected together (hint: you may need to burn or scrape off the insulation at the ends). Try a continuity test between each of the three wires to see if they are somehow shorting. Make sure you are not running into some sort of rubbing between the core and the rotor that is preventing it from spinning freely by hand: if so, try printing the rotor at 102-103%, which should keep the magnets tight but provide a little play between the core. Also, thinner wire is more useful for a lower-speed generator application vs. a motor and we've found it may take a slight hand-start to get it moving; the wire recommended for the motor should turn without assistance. If you still have issues please send us some pictures and comments to support@makesea.com and we'll do our best to assist further.
+1 (1 Vote)
Posted on 2/15/17 12:01 AM in reply to Michael Strong.
Hi guys,
I have tweaked some dimensions and now I am winding the stator with 0.22mm wire. just wondering if I can do the winding of an entire phase A and then the entire phase B and then the entire phase C? instead of going coil by coil as per instructions.
Thanks emoticon
+1 (1 Vote)
Posted on 4/10/17 11:21 AM.
Hi Carlos,
Yes, that should work, OK. The overlapping winding that is described is primarily to help manage the space issues with the thick wire and channels. As long as the phases are wound with the correct distribution vs. the magnets, you should get a similar result. Note that we do have a version wound with very thin wire for the lower-output generator application used in the windpowerWriter wind turbine project. What we discovered is that more windings with thinner wire works better for that application (energy capture at lower speeds). But, will likely provide less power output for the motor. You can also experiment with a 2-phase winding. Stay tuned for an even more powerful version of the makeSEA motor - coming soon!
+2 (2 Votes)
Posted on 4/10/17 12:35 PM in reply to Carlos Barreto.
Cool!, at this moment I am half way of finishing the winding. actually I used that wire based on the windpower writer because my interest is to make an efficient 3d printed generator. The changes I made use 10 poles instead of 12, I am not using Magnetic filament, so to compensate this I am using the magnets in an arrangement that allows me to point the magnetic field towards the stator. I would like to share my findings and discuss the changes. Looking forward to see your new motor.
Best regards.
Carlos
+1 (1 Vote)
Posted on 4/10/17 12:44 PM in reply to Chris Stavros.
A question was asked:
Is it possible to achieve at least 15amp of supply current using the printed bldc setup?

Christoph replied:
The makeSEA motor can be supplied with 15A, if the diameter of the copper wires for the windings is at minimum 0.85 mm.

Rotation speed should be over 8'000 rpm in order to provide enough ventilation (i.e. the load shall not be to heavy, so that rpm would drop below that limit). And the battery voltage needs to be low enough to not exceed 15'000 rpm (because of the catastrophic limit at 30'000 rpm).

Also be sure to check out the new more powerful 600 Watt Haibach Array motor design capable of handling between 20A and 80A - SEE https://www.makesea.com/makesea/1gt
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Posted on 5/5/17 12:44 PM.
Hey Christoph I accidently bought 20 of the wrong bearings is there any way you would be able to post a .ipt of the stator shield
+1 (1 Vote)
Posted on 5/5/17 4:46 PM.
Another useful related comment from Christoph: "The voltage also needs to be considered. The product of Current and Voltage can not exceed 120W for the makeSEA motor. With 15A the maximum voltage is about 8V. And the cross-section of the copper-wires needs to be adjusted to the current. The larger the current, the larger the required cross-section (and the less the maximum voltage)."
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Posted on 5/15/17 10:29 PM in reply to Maker Support.
Hi, I've managed to find all the parts but the shaft collar like eric eric mentioned. I was wondering if I could buy one from you guys as you mentioned you'd be selling those parts.
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Posted on 7/18/17 8:49 AM in reply to eric eric.
Hello Nicholas, we have complete kits available from the Mash Market. I will have someone reach out to you concerning the shaft collar part. Thank you.
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Posted on 7/18/17 11:14 AM in reply to Nicholas Saizan.
if i use PETG or ABS in Rotor, it doesn't explode when i use 6s????
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Posted on 8/22/17 7:23 AM.
Muchísimas gracias
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Posted on 11/30/17 9:21 PM.
Hi Christoph! I would like to ask you why you haven't traced BH curve for magnetic PLA yet, i believe the saturation's induction for this material is very low, if this is true maybe there's no need of it. Anyway i'm designing my own motor for ebike and i would like to share you. At moment i'm running finite elements analysis. Please let me know if you like to work with me (i'm electrical eng). Comunque ho visto che sei svizzero, se parli Italiano potremmo capirci meglio! Fammi sapere, e ancora complimenti per i tuoi lavori
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Posted on 12/7/17 12:33 AM.
Hi Nicola,

Thank you for your post. Please see the articles on the materials analysis at the Wiki: https://www.makesea.com/wiki

We are very excited to work with designers that are interested in evolving the makeSEA designs. The primary purpose of makeSEA is to enabled mashups, keep track of lineage, and to help enforce attribution, and compensation for original work when the creator chooses.

You can post your progress on your makeSEA Profile page Blog. Stay tuned for major enhancements to the project management interface, too.

Thanks for being a part of makeSEA!
+1 (1 Vote)
Posted on 12/12/17 5:12 PM in reply to Nicola Barlabà.
Hi Nicola. Your question about the "BH curve" ... Do you know a simple method how to measure it? Actually I had in mind to build two motors with identical winding, but different materials, and compare the efficiency. I'd expect that Kv is different, but the efficiency is unchanged. Unfortunately I didn't yet find time to do this experiment as it's quite some effort. Cheers, Christoph
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Posted on 1/12/18 10:56 AM in reply to Nicola Barlabà.
Hi Christoph i'm very happy for the answer, thank you! As you i believe that the only improvement was on Kv just because the permeability of magnetic pla is too low, so i think that good design can show that there's no need of magnetic one. First of all i would switch from radial to axial flux design. After few simulation i found that is it possible to achieve something like 0.5 V/(turn*slot) with this design and such perfect sine wave on 72 slot stator. My pain is the mechanical drawing emoticon
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Posted on 1/12/18 12:15 PM in reply to Christoph Laimer.
Hi Michael, I have a question for school. How did you measure the effeciency and the motor force of your motor?
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Posted on 2/20/18 6:01 AM.
Hi Christoph Laimer,
I was wondering if polycarbonate works as well as ABS and PETG?
Thanks!
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Posted on 4/18/18 9:13 AM.
Hi Garrett. I'm not really experienced with polycarbonate. I guess its strength is even better than PETG. Not sure about shrinkage - that's maybe an issue with fitting individual parts together.
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Posted on 4/21/18 2:14 AM in reply to Garrett Smith.
This project is very interesting. As soon as I saw it I quickly ordered magnetic Iron PLA and printed a very rough motor of own design in under two hours and it actually ran. Only about 100 RPM but good enough as a POC and I am now printing your first version to follow your process and get a better understanding of the designs. I first and foremost want to thank you for sharing your work. I can't wait to test my copy in a few days and tinker with it.
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Posted on 9/22/18 6:41 PM.
Hi Gudmundu, really glad you like the project! Don't forget to check out Christoph's 600W version of this Halbach Array style brushless motor, here: https://www.makesea.com/makesea/1gt
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Posted on 9/24/18 12:12 PM in reply to Gudmundur Karl Karlsson.
Can you make a brushed dc motor size FC130RA with multi poles magnet and make tutorial for drawing?
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Posted on 7/4/19 10:42 AM.
I noticed on your 600w improved/bigger motor you used a Halbach Array for the magnets ... It makes me wonder if you could do the same with this motor, if so, what would be the expected gains if any?

I'm tempted to try my hand at making a rotor for the magnets to be used in a Halbach Array ...using your 600w motor as a guide to know the number of minimum magnets and so work out the size of magnet I'd need.If I understand correctly, a Halbach Array essentially doubles the number of magnets needed to create each "pole" for the motor?
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Posted on 7/9/19 6:10 PM.
Can you send this file to my email Scythekronos68@gmail.com I am sorry please! or your browser doesn't understand how to supply the credentials required.
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Posted on 7/20/19 9:08 AM.
Hi, thanks for the project! It is awesome! By the way, some download links are broken, could you please fix it?
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Posted on 9/6/19 8:07 PM.
Can we get more details on winding, maybe some simulation or more step by step video please.
+1 (1 Vote)
Posted on 11/29/19 10:34 PM.
what type of winding is used in the second version.
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Posted on 11/29/19 10:36 PM.
Hello Mr. Laimer,

I have built the 3D printed 90W brushless motor and it is not turning.

My setup is:

*** 30A ESC.
*** Servo tester.
*** 2S Lipo battery.

The motor beeps before i connect the servo tester and then it stops beeping. When i dial up the nob of the servo, the motor produces quiet sparky sound and the ESC heats up a bit.

BTW, i used 0.8 mm wire and 2 turns per tooth because the 1 mm is too thick and it breaks my stator when i wind with it.

It might be that the winding is not so accurate.. can i please send you a picture and check it?

Thank you for sharing the project.
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Posted on 12/9/19 10:57 AM.
Hi aza zaz,

I have drawn the full windings for each phase on my ipad and it helped me big time. If you want, i can send you the pictures.. just send me your email.

BTW, i just finished my motor but it is not turning and i am not sure why.
+1 (1 Vote)
Posted on 12/9/19 11:20 AM in reply to aza zaz.
Hello Zakaria, it sounds like there may be a short somewhere in your windings. Are you sure that the wire that you used has a non-conductive coating? Using wire without a coating would produce a similar symptom. Try a continuity test between the three pole leads at various points in the winding. If there is a short, it is probably uncoated wire.
0 (0 Votes)
Posted on 12/9/19 12:32 PM in reply to Zakaria Alkhamees.
Thanks for replying!

The wire is coated with non conductive coating and i have done the continuity test many times.. all of them are successful. I get a beep whenever i connect the multimeter with two leads.

I think the winding is a bit strange.. please look at the picture of the stator and my setup.

Thanks a lot.
0 (0 Votes)
Posted on 12/10/19 9:14 AM in reply to Maker Support.
Hi,

In version 2 windings, should the ending wires meet with the starting wires in the same slot when finishing with the winding?

Every ending wire on my stator is 2 slots apart from the starting wire.. is this correct?
+2 (2 Votes)
Posted on 12/11/19 3:24 AM.
Hi,

If you don't mind telling us what kinda of battery you used in you Rc Plane, can you give us the exact name of the battery please ?
+1 (1 Vote)
Posted on 12/15/19 5:59 PM.
Hi aza zaz,

The lipo battery i have used was a 2 cell 7.4 V and 25C. The brand of the battery is SL TOYS. It is an unknown chinese brand.

I think the reason why my motor hasn't turned was because i used 0.8 mm with 2 turns on each tooth which wasn't enough to create a strong magnetic field and affect the rotor. I have used a 1mm wire for winding but it didn't go well; the stator kept breaking on me since it is very brittle (Iron pla from proto pasta) until it was useless. honestly the stator print was not so good; it had some splits and cracks. I will try to print a perfect stator and wind it with a 1mm wire again, but my printer is on maintenance for now.

Thanks.
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Posted on 1/9/20 4:24 PM in reply to aza zaz.
Hi Christophe,

I made your 600W motor and succesfully assembled it. But the motor needs a slight hand push to start rotating. I have manage to scrapped all the pieces to get them turning freely but it still needs a push. When i turn it by hand without power, i hear a bit of noise from the magnet (attractive magnetic fields probably). I run it with a 12V battery for the test and with a standard ESC.

I’m out of solution and i need help, it’s the last problem i have. If you need video or info just reach at raphaelgau12@hotmail.com

Raphael
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Posted on 4/2/20 10:08 PM.
hello i can't download some files What is the reason?
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Posted on 5/5/20 5:21 AM.